JP2012076512A - Steering-support-member reinforcing structure of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering-support-member reinforcing structure, capable of enhancing impact resistance to an impact load from a front side of a vehicle and vibration resistance inexpensively.SOLUTION: The steering-support-member reinforcing structure includes: a lower brace 4 connecting an intermediate part in a vehicle width direction of a steering support member 2 and a floor tunnel upper part 10; and a base bracket 5. The base bracket 5 has: a peripheral flange part 51 to be a joining part to the floor tunnel upper part 10; and a central swelling part 52 enclosed by the peripheral flange part. Here, a closed cross section is formed between the base bracket and the floor tunnel upper part 10. The lower brace 4 has: a body part (40, 41, 42) extending in nearly vertical directions; and a lower end part 43 extended in the vehicle width direction to the body part via a bending part. Then, the lower brace 4 is connected to the floor tunnel upper part 10 via the base bracket 5 by screwing and fastening a bolt 34, inserted into a bolt insertion hole 45 of the lower end part 43, to a rear part upper surface 53 (a weld nut 35) of the base bracket 5.

Description

  The present invention relates to a structure for reinforcing a steering support member of an automobile, and more particularly, to a structure for connecting a middle portion of a steering support member in the vehicle width direction and an upper portion of a floor tunnel.

  A steering support member for connecting left and right vehicle body side walls (dash side panels) in the vehicle body width direction is disposed in the front part of the passenger compartment of the automobile. A steering column is supported on the driver's seat side of the steering support member, and heavy components such as an instrument panel, in-vehicle audio, and air conditioning equipment are suspended. The steering support member is made of a steel pipe and the like, and is a rigid member having a predetermined strength and rigidity, but it is a long member extending over the entire width of the passenger compartment, so that it is difficult to ensure rigidity by itself. It is.

  If the rigidity around the steering support member is low, the vibrations of the steering are transmitted to the driver, causing discomfort, and squeaking noise is generated due to vibrations of the devices. In addition, when an impact load is applied from the front of the vehicle due to a collision accident and the upper part of the dash panel and the cowl panel are deformed into the vehicle interior, the steering support member is deformed rearward and the steering wheel moves backward. Backward movement should be kept to a minimum.

  Therefore, in order to compensate for the rigidity of the steering support member itself and the coupling rigidity to the vehicle body, and to improve vibration resistance and impact resistance characteristics, an upper brace that connects the steering support member and the cowl panel in the front-rear direction, and the steering support member And a reinforcing member such as a lower brace for connecting the floor tunnel portion in the vertical direction (see, for example, Patent Document 1).

  There may be a case where an intentionally weak portion is set in the upper brace. When an impact load from the front of the vehicle is applied, the upper brace is buckled and deformed at an early stage so as to absorb the impact and simultaneously reduce the impact on the steering support member. However, until the upper brace is deformed and after the deformation, the load from the front is applied to the steering support member, and during that time, the lower end joint of the lower brace is subjected to a tensile force and bending stress directed rearward and upward. It will be.

  Therefore, when the joint rigidity and joint strength at the floor tunnel portion of the lower brace are low, it cannot be expected to contribute to impact resistance. The panel constituting each part of the vehicle body is limited in thickness for weight reduction, and the floor tunnel portion (the front end portion of the floor panel or the lower end portion of the dash panel) to which the lower brace is coupled is no exception. Since the lower end portion of the lower brace disclosed in Patent Document 1 is fixed by a bolt that penetrates a bracket welded to the upper surface or the side surface of the right end of the floor tunnel portion, the coupling rigidity against the backward bending stress is obtained. In addition, the spot where the bracket is spot-welded to the floor tunnel portion is limited, and it is not expected to improve the bonding strength with respect to the tensile force toward the rear upper side.

  In addition to the above, there is also a reinforcing structure in which two braces are extended from the steering support member on both sides of the floor tunnel portion (see, for example, Patent Document 2). However, such a reinforced structure causes a deterioration in fuel consumption due to an increase in vehicle weight and an increase in production cost due to an increase in the number of parts and processing man-hours. There is a problem that it is difficult to secure a space around the pedal.

Japanese Patent Laid-Open No. 57-4466 JP-A-7-81376

  The present invention has been made in view of such a situation, and an object thereof is to provide a reinforcement structure for a steering support member that can improve impact resistance characteristics and vibration resistance characteristics against an impact load from the front of the vehicle at a low cost. There is to do.

  In order to solve the above-described problems of the prior art, a steering support member reinforcing structure according to the present invention is configured to connect the steering support member (2) in the vehicle width direction intermediate portion and the floor tunnel upper portion (10). And a base bracket (5) joined to the upper part of the floor tunnel, and the base bracket (5) is a peripheral flange part serving as a joint part to the upper part of the floor tunnel. (51) and a central bulge portion (52) that is surrounded by the peripheral flange portion and forms a closed section between the upper portion of the floor tunnel, and the central bulge portion is substantially a vehicle longitudinal direction. The weld nut (35) is fixed to the rear surface side of the through hole formed in the rear upper surface having a rear upper surface (53) inclined downward from the center to the rear lower surface. On the other hand, the lower brace (4) includes a main body portion (40, 41, 42) extending in a substantially vertical direction, and a lower end portion (43) extending in the vehicle width direction via a bent portion with respect to the main body portion. And a bolt insertion hole (45) corresponding to the through hole is formed in the lower end portion, and the bolt (34) inserted through the bolt insertion hole is provided on the upper surface of the rear portion. By screwing and fastening the weld nut (35) through the through hole, the lower end portion (43) of the lower brace (4) is connected to the floor tunnel upper portion (10) via the base bracket (5). Has been.

  In a preferred aspect of the steering support member reinforcing structure according to the present invention, the main body portion of the lower brace includes an upper end portion (40) extending downward or rearward downward from an upper end rigidly coupled to the steering support member (2), The main part (41, 42) which inclines in the front downward direction via the bending part is included in the lower side (FIGS. 1, 2).

  In a further preferred aspect of the steering support member reinforcing structure according to the present invention, the base bracket (5) includes a floor-side floor tunnel upper portion (12b) extending substantially horizontally in the vehicle front-rear direction, and a front-upward upward direction. It is joined across the bent part (12c) with the floor tunnel upper part (12a) on the dash panel side having an inclination, and the peripheral flange part (51) is a floor side flange part (51b) extending substantially horizontally. ) And a dash panel side flange portion (51a) having an upwardly inclined upward direction, and in a side view between the central bulge portion (52) and the upper portion of the floor tunnel (10, 12a, 12b) A closed cross section having a substantially diamond shape is formed (FIGS. 2 and 3).

  In another preferred aspect of the steering support member reinforcing structure according to the present invention, the upper part of the floor tunnel (12a, 12b) to which the base bracket is joined is a joint between the dash panel (12) and the floor panel (11). It is on the dash panel (12) side adjacent to (18).

  Since the steering support member reinforcing structure according to the present invention is configured as described above, the following effects can be obtained.

  The base bracket (5) has a peripheral flange portion (51) to be a joint to the floor tunnel upper portion (10), and a central bulge portion (52) surrounded by the peripheral flange portion, and the central bulge portion The lower end (43) of the lower brace is fixed with bolts (34) on the rear upper surface (53) inclined downward and rearward, so that many spot welding points for the upper part of the floor tunnel are secured at the peripheral flange of the base bracket Each spot welding point is distributed radially around the bolt fastening point with the lower end of the lower brace, so that the base bracket is interposed between the lower end of the lower end brace and the upper part of the floor tunnel. Bond strength is obtained.

  Further, the closed cross section is formed between the base bracket (5) and the floor tunnel upper part (10), so that the rigidity of the upper part of the floor tunnel in the vicinity of the lower end of the lower brace is improved, and the lower end of the lower brace and the base bracket are By securing a sufficient joint seat surface between the rear upper surface and the lower end portion of the lower brace and the upper portion of the floor tunnel, good coupling rigidity can be obtained via the base bracket.

  As described above, good joint strength and bonding rigidity can be obtained via the base bracket between the lower end of the lower brace and the upper part of the floor tunnel, and the load can be distributed widely and evenly over the upper part of the floor tunnel. Thus, when an impact load from the front of the vehicle is input to the steering support member, it is possible to obtain a good reinforcement structure that can resist the tensile force and bending stress applied to the lower end of the lower brace by the impact load. This is advantageous in improving the impact resistance characteristics and vibration resistance characteristics with respect to the impact load.

  In addition, the center bulge portion (53) of the base bracket only needs to have a bulge amount that is about the thickness of the weld nut and bolt, and remains in a relatively flat shape. In addition, it is advantageous in terms of production cost because spot welding can be easily performed and the number of parts and processing man-hours are not increased. Moreover, since the protrusion to the vehicle interior space is small and the bulging shape is along the upper portion of the floor tunnel, it is advantageous in terms of securing the space around the driver's pedal.

  In the present invention, the body portion of the lower brace includes an upper end portion (40) extending downward or rearward from the upper end rigidly coupled to the steering support member (2), and a front lower portion via a bent portion below the upper end portion (40). In the aspect including the main parts (41, 42) extending obliquely to the rear, the extension direction of the main part of the lower brace is substantially perpendicular to the upper surface of the rear part of the base bracket, and the rear upper part inputted through the lower brace By receiving the tensile load on the surface perpendicular to the load, the bending stress at the joint via the base bracket can be reduced, and the tensile force that peels off the weld point on the front side in the vehicle longitudinal direction of the base bracket is reduced. It is advantageous for improving the joint strength of the base bracket and for improving the impact resistance against the impact load from the front of the vehicle.

  In the present invention, the base bracket (5) includes a floor-side floor tunnel upper portion (12b) extending substantially horizontally in the vehicle front-rear direction and a dash panel-side floor tunnel upper portion (12a) having an upwardly upward slope. And the peripheral flange portion (51) is a floor-side flange portion (51b) extending substantially horizontally, and a dash having an upwardly inclined upward direction. A mode in which a closed cross section having a substantially rhombus shape is formed between the central bulging portion (52) and the upper portion of the floor tunnel (10, 12a, 12b) including the panel side flange portion (51a). Then, the bent portion of the dash panel is reinforced by a three-dimensional base bracket that forms a closed cross section that intersects the bent portion and extends in the front-rear direction. It is possible to suppress.

  In the present invention, the upper part of the floor tunnel (12a, 12b) to which the base bracket is joined is located on the dash panel (12) side adjacent to the joint (18) between the dash panel (12) and the floor panel (11). In one embodiment, while a dash panel having a relatively thin plate thickness is used as a bonding surface with the base bracket, the surface rigidity of the surrounding area is secured by a bonding portion that is overlapped with the floor panel and increases the plate thickness, and good bonding strength is obtained. .

It is the perspective view which looked at the steering support member vicinity of the motor vehicle which enforced the reinforcement structure which concerns on this invention from the vehicle interior back. It is a perspective view which shows the connection part of the lower brace lower end part and floor tunnel upper part which implemented the reinforcement structure which concerns on this invention. It is side sectional drawing which shows the connection part of the lower brace lower end part and floor tunnel upper part which implemented the reinforcement structure which concerns on this invention. It is YY sectional drawing of FIG. It is the perspective view which looked at the base bracket which concerns on this invention embodiment from the vehicle interior back.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, a cowl top panel 13 extending in the vehicle width direction along the lower edge of the front window is joined to an upper portion of a dash panel 12 that defines a front part of a compartment of the automobile 1. The left and right sides of the dash panel 12 are joined to dash side panels 14 and 15 that constitute a part of the side wall of the vehicle body.

  A steering support member 2 extending in the vehicle width direction is disposed behind the dash panel 12. Brackets 21 and 22 are fixed to the left and right ends of the steering support member 2, and the steering support member 2 is fixed to the left and right dash side panels 14 and 15 via these brackets 21 and 22. .

  The steering support member 2 is composed of a straight steel pipe having a circular cross section, and a pair of brackets for attaching the steering column 6 schematically shown in the drawing to the large-diameter portion 2a on the driver's seat side on the right side in the drawing. While 23 and 23 are fixed, the passenger seat side on the left side in the figure is configured to have a relatively small diameter, thereby reducing the weight. An upper brace 3 extends from the steering column mounting portion (23, 23) of the steering support member 2 toward the front and slightly obliquely upward, and the front end of the upper brace 3 is fixed to the cowl top panel 13.

  A tapered portion 2c is provided between the large-diameter portion 2a and the small-diameter portion 2b of the steering support member 2, and a lower brace 4 is directed downward on the large-diameter portion 2a of the steering support member 2 adjacent to the tapered portion 2c. It is extended. In addition, on the small diameter portion 2b side of the steering support member 2 adjacent to the taper portion 2c, a stay 24 for mounting on-vehicle devices (vehicle audio, car navigation system, etc.) not shown and vehicle-mounted air conditioners 8a and 8b are provided. A stay 25 for suspension is extended downward.

  The lower brace 4 includes a main body upper portion 41 (lower brace upper) including an upper end portion 40 welded to the steering support member 2, and a lower main body portion 42 including a lower end portion 43 joined to the floor tunnel upper portion 10 via the base bracket 5. The main body upper portion 41 and the main body lower portion 42 are rigidly connected by two bolts 32 and 32 and weld nuts 33 and 33 which are fastened through the overlapping portions thereof.

  The upper body 41 of the lower brace 4 has a length that is about 2/3 of the entire lower brace 4 and is press-molded into a U-channel shape that is flat in the vehicle width direction. The stay 24 extends parallel to the stay 24 and is connected to the stay 24 by a bar. The main part of the main body upper portion 41 is inclined downward and forward with a bent portion below the upper end portion 40.

  As shown in FIG. 2, the lower body 42 of the lower brace 4 has a main part extending on the extension of the upper part 41 and a lower end extending in the vehicle width direction via a bent part below the main part. And a bolt insertion hole 45 in the lower end 43. The main body lower portion 42 is press-molded into a flat U-channel shape similar to the main body upper portion 41, but two reinforcing beads 42a and 42a extending in the vertical direction are formed at the central portion of the main portion. Further, the rigidity is increased, and these reinforcing beads 42a, 42a reach the lower end portion 43 through the bent portion, and the lower end portion 43 detours so as to form a flat portion around the bolt insertion hole 45. It is continuous with the flanges on both sides.

  A base bracket 5 for reinforcing the joining surface of the lower end portion 43 is disposed on the floor tunnel upper portion 10 to which the lower end portion 43 of the lower brace 4 is joined.

  As shown in FIGS. 2 to 5, the base bracket 5 has a flat cup shape having a peripheral flange portion 51 that is a joint portion to the floor tunnel upper portion 10 and a central bulging portion 52 surrounded by the peripheral flange portion 51. The closed section is formed between the central bulging portion 52 and the floor tunnel upper portion 10.

  The center bulging portion 52 has a rear upper surface 53 that is inclined rearward and downward with a ridge line extending in the vehicle width direction as a boundary at the approximate center in the vehicle front-rear direction, and at the approximate center of the rear upper surface 53, as shown in FIG. A through hole 55 corresponding to the bolt insertion hole (45) of the lower brace lower end 43 is formed, and a weld nut 35 is welded and fixed to the back side thereof as shown in FIGS. 4 and 5, a claw hole 54 is formed adjacent to the through hole 55 in the rear upper surface 53, and projects downward from the edge of the lower end portion 43 of the lower brace. By engaging the claw 44, positioning and rotation prevention when the lower end portion 43 of the lower brace is fastened and fixed by the bolt 34 are possible.

  As shown in FIG. 5, the base bracket 5 is spot-welded at seven locations distributed on the peripheral flange portion 51 surrounding the central bulging portion 52 and joined to the floor tunnel upper portion 10. A footrest base 17 is spot welded to the floor inclined surface (dash panel 12) on the right side of the base bracket 5 in the drawing. A dash reinforcement 16 extending in the vehicle width direction is joined to an upper portion of the floor inclined surface of the dash panel 12.

  The joining surface of the floor tunnel upper part 10 of the base bracket 5 is on the dash panel 12 adjacent to the joining part 18 where the edges of the dash panel 12 and the floor panel 11 are overlapped and welded. This joint surface straddles the bent portion 12c of the floor tunnel upper portion 12b on the floor side that extends substantially horizontally in the vehicle front-rear direction and the floor tunnel upper portion 12a that has an upward slope toward the front upper side on the front side, The peripheral flange portion 51 of the base bracket 5 has a floor-side flange portion 51b extending substantially horizontally and a dash panel-side flange portion 51a having an upward slope upward. With this configuration, a closed section having a substantially rhombus shape is formed between the central bulging portion 52 of the base bracket 5 and the floor tunnel upper portion 10 (12a, 12b) in a side view (FIG. 3).

  As described above, the steering support member 2 is reinforced in the front-rear direction with the upper brace 3 and reinforced in the vertical direction with the lower brace 4 to improve the vibration resistance. In addition, when an impact load acts from the front of the vehicle due to a collision accident or the like and the upper part of the dash panel and the cowl panel are deformed into the vehicle interior, the impact load is input to the steering support member 2 through the upper brace 3, The impact is absorbed by the buckling deformation of the upper brace 3 whose rigidity is adjusted moderately, and the impact on the steering support member 2 is mitigated, but the load from the front also during and after the deformation of the upper brace 3 Is added to the steering support member 2, and during that time, the lower end joint portion (43) of the lower brace 4 is subjected to a tensile force F or a bending stress M directed rearward and upward as shown in FIG. In addition to the tensile strength and bending strength of the lower brace 4, the lower end joint (43) of the lower brace 4 has a fixed rigidity. It is also the same as those already mentioned is important in order to suppress the rearward movement of the ring support member 2 (the steering wheel).

  In this regard, the reinforcing structure according to the present invention is such that the base bracket 5 serving as the attachment portion of the lower brace lower end portion 43 is surrounded by the peripheral flange portion 51 serving as a joint portion to the floor tunnel upper portion 10 and the peripheral flange portion. With the structure in which the lower end portion 43 of the lower brace is fixed to the rear upper surface 53 of the central bulging portion 52 with the bolts 34, many spot welding points can be secured around the base bracket 5, Each spot welding point is radially distributed around the bolt fastening point (34, 54) with the lower brace lower end 43, so that the base bracket 5 is placed between the lower brace lower end 43 and the floor tunnel upper part 10. Thus, good bonding strength can be obtained.

  In addition, since the closed cross section is formed between the base bracket 5 and the floor tunnel upper portion 10, the rigidity of the floor tunnel upper portion 10 in the vicinity of the lower brace lower end portion 43 is improved, and the lower brace lower end portion 43 and the base bracket 5 are By securing a sufficient joint seat surface between the rear upper surface 53 and the lower end portion 43 of the lower brace and the upper portion 10 of the floor tunnel, good coupling rigidity can be obtained via the base bracket 5.

  Therefore, as described above, in addition to the improvement in the bonding strength and the coupling rigidity between the lower end portion 43 of the lower brace and the floor tunnel upper portion 10, the tensile force F and the bending force are applied to the floor tunnel upper portion 10 in a wide range and evenly. By dispersing the stress M, it is possible to obtain a good reinforcing structure and shock absorbing structure that can counter these, and it is advantageous in improving the impact resistance.

  Further, the central bulging portion 53 of the base bracket 5 only needs to have a bulging amount about the thickness of the weld nut 35 and the bolt 34, and remains in a relatively flat shape. It is possible to form by the drawing process, and to avoid the increase in the number of moldings and the cost increase due to the added mold cost. In addition, there is little protrusion into the vehicle interior space, and the bulging shape along the floor tunnel upper part 10 has no effect on the layout of the shift cable, ducts, floor console, etc., and the space around the driver's pedal is secured. This is also advantageous.

  Moreover, since the rear upper surface 53 of the central bulging portion 53 forms an inclined surface toward the vehicle interior side, the bolt 34 can be easily fastened even after the instrument panel is mounted. Further, the through holes 55 and the weld nuts 35 for fastening the bolts 34 are completely inside the vehicle interior, and no bolt fastening holes are required in the dash panel 12 or the floor panel 11. There is no worry about leakage.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention. .

DESCRIPTION OF SYMBOLS 1 Automobile 2 Steering support member 3 Upper brace 4 Lower brace 5 Base bracket 10, 12a, 12b Floor tunnel upper part 11 Floor panel 12 Dash panel 12c Bending part 34 Bolt 35 Weld nut 40 Upper end part 41 Main part upper part (main part)
42 Lower part of main body (main part)
43 Lower end portion 44 Claw 45 Bolt insertion hole 51 Peripheral flange portion 51a Dash panel side flange portion 51b Floor side flange portion 52 Center bulge portion 53 Rear upper surface 54 Claw hole 55 Through hole

Claims (4)

A lower brace rigidly coupled to the steering support member to connect the intermediate portion of the steering support member in the vehicle width direction and the upper portion of the floor tunnel;
A base bracket joined to the upper part of the floor tunnel,
The base bracket has a peripheral flange portion to be a joint to the floor tunnel upper portion, and a central bulge portion that is surrounded by the peripheral flange portion and forms a closed cross section with the floor tunnel upper portion, The central bulge portion has a rear upper surface inclined rearward and downward from a substantially center in the vehicle front-rear direction, and a weld nut is fixed to the rear surface side of the through hole formed in the rear upper surface,
The lower brace has a main body portion extending in a substantially vertical direction and a lower end portion extending in a vehicle width direction with respect to the main body portion via a bent portion, and the through hole is formed in the lower end portion. Bolt insertion holes corresponding to are drilled,
The lower end portion of the lower brace is connected to the upper portion of the floor tunnel via the base bracket by screwing and fastening the bolt inserted into the bolt insertion hole to the weld nut through the through hole on the upper surface of the rear portion. Car steering support member reinforcement structure that is being.   The main body of the lower brace includes an upper end that extends downward or rearward from the upper end rigidly connected to the steering support member, and a main portion that extends downward and inclined forward and downward via a bent portion. The steering support member reinforcing structure for an automobile according to claim 1, comprising:   The base bracket is joined across a bent portion between a floor tunnel upper portion on the floor side extending substantially horizontally in the vehicle front-rear direction and a dash panel side floor tunnel upper portion having an upward inclination to the front upper side. The peripheral flange portion includes a floor-side flange portion extending substantially horizontally and a dash panel-side flange portion having an upward inclination to the front upper side, between the central bulge portion and the upper portion of the floor tunnel, The steering support member reinforcing structure for an automobile according to claim 1 or 2, wherein a closed cross section having a substantially rhombus shape is formed in a side view.   The steering support member reinforcing structure for an automobile according to claim 1, 2, or 3, wherein an upper portion of the floor tunnel to which the base bracket is joined is located on a dash panel side adjacent to a joint portion between the dash panel and the floor panel.

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